Governor apparatus



July l 194 o. N. BRYANT 2,247,434

' eovERNoR APPARATUS Filed June 28, 1959 ATTORNEY Patented July 1,` 1941GGVERNOR 4APPARATUS Ozro Newton Bryant, Prospect' Park, Pa., assignor toWestinghouse Electric 6;` Manufacturing Company, East Pittsburgh, Pa., acorporation of Pennsylvania Application June 28, 1939, Serial No.281,607

8 Claims.

My invention relates to a governing system of the pressure transformertype which is operative in response to a change in primaryor'controlling force to provide a change in secondary or transformedfluid pressure in predetermined relation with respect thereto and it hasfor an object to provide apparatus of this `character which is durable,substantially frictionless, relatively simple in design, and economicalto build and operate.'

A further object of my invention is to provide apparatus of the abovecharacter including means to secure operation such that the regulatingpercentage is reduced or eliminated. 1

A further object of my invention is to provide a pressure transformerwherein the magnitude of transformed fluid pressure is determined by anescape port with a. valve in covering relation with respect thereto, thevalve being positioned by a primary controlling force and by the forceof transformed fluid pressure acting thereon.

These and other objects are effected 'by my invention as will beapparent from the following description and claims takenin connectionwith the accompanying drawing, forming a partof this application, inwhich:

Fig. 1 is a sectional view showing my improved pressure transformerapplied` to govern a steam turbine; and,

Fig. 2 is a View, similar to Fig. l, but showing a modified form of thetransformer.

Referring to the drawing more in detail, the` turbine apparatus, theadmission valve, and the servo-motor for controlling the latter Awill bereferred to rst in order to make the operation of the transformerclearer.

In Fig. `1, there is shown a steam turbine l0 having an admission valveIl operated by a servo-motor, at` l2, the servo-motor includingoperating and pilot valve cylinders I3 and I4, the pilot valve cylinderhaving the pilot valve I5 therein controlling the admission and exhaustof suitable motive fluid to opposite sides of the operating piston i6carried by the rod l1, the latter being connected, by suitable linkage,to the admission valve.

The pilot valve i5 is operated by means of a pressure-responsive deviceI8 having a pressure space dened by the movable abutment I9 and thecooperating bellows elements 20 and 2|.

Follow-up mechanism, is arranged between the operating piston and thepiston valve to bring about restoration of the latter to neutralposition in consequence of movement of the operating piston. To thisend, the operating piston.

rod Il is connected, by means of a lever 22, to one end'of a spring 23,the other end. of the latter being connected to the pilot valve, as iswell known in the art.

Referring now to the means for developing a primary or controlling forcewhich is utilized by the pressure transformer to secure a transformedfluid pressure for applic-ation to the pressure-.responsive device I8,any suitable means may be used to provide this force, for example, theturbine spindle 24 is shownas having a suitable' impeller 26, whichsupplies oil under pressure to the passage 2l, the fluid pressurevarying substantially as the square of the speed.

The passage 2l supplies oil under impeller pressure to the pressuretransformer, at 28, the latter operating', in response to change inimpeller pressure to provide a change in transformed oil pressure inpredetermined relation with respect thereto and supplying suchtransformed oil pressure by means of the passage 29. tothe pressureresponsive device IB.

The pressure transformer, at 28, includes a body structure 30 havingupper and lower chambers at; 3l and 32. As shown, the body is comprisedby stacked sections 33, '34 and 35, the intermediate and top sectionshaving transverse walls 36 and 3l. The sections are clamped together byany suitable means, for example, bolts (not shown). The upper chamber 3lis a part of the exhaust or drain space and the lower chamber isconnected to receive fluid under primary or impeller pressure. i

The upper transverse Wall 3l has a radial passage 39 terminating in anaxial discharge port 40 and the discharge end of the latter is boundedby a at or seat surface 4| with which cooperates the cup valve 42.

The interiors of the pressure-responsive device I8, the passages 29 and39 and the port 40 constitute a transformed iiuid pressure space towhich oil is supplied by any suitable means such that the magnitude' ofpressure in the space will depend upon the annular escape orificeprovided by the cup valve 42 cooperating with the seat 4|. For example,an orifice 43 is shown for supplying the space from any suitable source.

Referring now to the means for applying forces to the cup valve 42 to`regulate the annular, radially-directed, escape orifice defined betweenthe sharp annular edge 44 and rthe fiat seat 4I, it will be obvious thatthe force of transformed oil pressure acts on the cup valve 42 in such adirection as vto tend to increase the flow area of the annular orifice.This force is opposed by a suitable primary orcontrolling force suchthat the annular orifice is regulated to secure a transformed oilpressure in predetermined relation to the primary controlling force.

Referring now tothe primary controlling force, by way of example, thebody 30 is shown as provided with the lower chamber 32 in communicationwith the impeller passage 21, such chamber being separated from thechamber 3| by a structure comprising an abutment 45 .connected by thebellows 46 to the inwardly-projecting annular plate 41 clamped betweenthe body sections 33 and 34. The force of impeller pressure applied tothe downwardly-facing piston area provided by the abutment 45 is opposedby means of the load spring 48 whose lower end is connected to suitablespeed change apparatus 49, as is well known in the art.

The abutment 45 is arranged/,to apply the resultant of the forces actingthereon by any suitable thrust structure, at 50, to the cup valve 42,the cup valve preferably having a conical seat cooperating with theconical tip 52 of the thrust structure to provide a point bearing.

From the structure so far described, it will be apparent that, if achange in primary pressure or force occurs, incident, for example, to achange in load of the turbine, such force is transmitted to the cupvalve 42 to regulate the annular escapeporiiice such that thetransformed oil pressure changes in predetermined relation with respectto the primary force or pressure change, the force of transformed oilpressure acting on the cup valve in opposed relation to the resultant ofthe force of the load spring and of the primary pressure or controllingforce.

Preferably, the thrust structure, at 50, is comprised by a central post53 having its lower end attached to the abutment 45 and having its upperend attached to the cross bar or plate 54 secured to the lower ends ofrods 55 whose upper ends are connected to the plate 56 carrying thecentral stem 51 whose upper end is provided with vthe conical tip 52. Inaddition to the stem 51 being connected to the plate 56, it serves toclamp the diaphragm 58 in place with respect thereto, the outer edge ofthe diaphragm being clamped between the body sections 34 and 35.

The diaphragm serves to center the thrust structure and provides formovement thereof without friction.

The intermediate transverse wall 36 has openings 66 through which therods 55 extend, the wall being provided with a passage 6| communieatingwith a central and upwardly-directed port 62. A bellows 63 has its lowerend attached to the wall 36 and its upper end attached to the plate 56,the bellows providing a pressure space, at 64, communicating with theport 62 and the passage 6|, and the piston or abutment area 65 providedon the plate 56 and encompassed by the bellows 63 being preferablyopposed and equal to the piston area of the cup valve encompassed by theannular orifice,

While the passage 6I communicating with the pressure space, at 64, maybe connected to the drain space, at which time it exerts no effect onthe transformer, I prefer to have it connected to the transformed oilpressure space so that pressure may be applied to the piston area orabutment 65 in lagging relation with respect to the transformed oilpressure applied to the cup valve,-the lagging pressure providing forspeed correction, in whole or in part, incident to change in load.

The passage 6l is shown as connected. to the transformed oil pressurespace `by means of a conduit 66 having an adjustable orifice 61. Anaccumulator, for example, an air bell 68, is arranged between theorifice and the space, at 64. the passage 66 is also provided with avalve 69 which is adjustable't'o vary communication of the conduit 66with the exhaust space or drain. With the valve 69 closed, then the fullelect of lagging pressure is applied to secure isochronous operation.rOn the other hand, as the valve 69 is opened to place the space 64 incommunication with the drain space, the maximum pressure obtainable inthe space, at 64, becomes less and less, with the result that the speedcorrection becomes less `,and less until finally, with the space, at 64,in communication with the drain and communication with the transformedoil pressure space cut off, the governing apparatus operates with itsfull percentage of regulation.

Movement of the apparatus for the purpose of varying the transformed oilpressure is very small so that the apparatus is essentially a forcetransmitting, utilizing, and transforming one without substantialmovements of any kind. It is desirable, therefore, to provide meansytolimit the downward movement, or determine the position at least; of thethrust structure, at 50. Therefore, the transverse plate 54 as shown isprovided with an edge 10 having close clearance with respect to theupper surface of the plate 41.'

The oil escapes from the annular orifice defined by the cup valve 42into the space, at 3i,

containing the diaphragm 58 having openings 59 providingcontinuity ofthe space.r The space also includes the passages 60, the space above theplate 41, and the interior space of the bellows 46. As the outlet 14 isat the top, the space will be maintained filled with oil, and, since theimpeller space 32 is also fllled with oil, high frequency vibrationswill be damped.

In Fig. 2, there is shown apparatus having the same operating principlesas that already described but wherein there is shown a furthermodification of thestructure. In this view, the thrust structure, at50a, has a single stem 53a whose upper end carries the conical pin 52a,the diaphragm 58 being clamped in place between a flange 14 and a nut15. The body structure 30a has upper and lower parts 35a and 33a held inplace by clamping screws (not shown), the parts clamping a compositeannular plate structure including the plate 36a and the upper and lowerplates luand 41a, the plates 'being arranged in superposed relation.

The upper plate 18 has a central opening 80 through which the stem -53aextends and a bellows encompasses the stem and has its upper endattached to the plate 18, the lower end of the bellows being connectedto an abutment 8i carried by the stem. The intermediate plate 36a has apassage Bla which communicates with the central opening thereof throughwinch the bellows extends, the plate having a depending cup` `:ascuas A3tics may be kept uniform so as to avoid pulsations of transformedpressure or disproportionate changes in the latter, I prefer to limitthe minimum orifice width. Preferably, the orifice width should not beless than 1/2 of the thickness of the edge 44. By having the apex of theconical seat or bearing 5i spaced below the seat 4l, it will be apparentthat the hydraulic reaction of fluid escaping from the annular oricetends to keep the edge 44 in parallel relation with respect to the seatso that a uniform circumferential discharge of uid occurs. Assuming thatthe cup should tilt so as to define a minimum orifice width at one sideand a maximum at the other, the increasing hydraulic reaction providedby the region of maximum width gives a force tending to tilt the cup soas to equalize the orice width. Thus the cup inherently tends to seek aposition so as to define an annular orifice of uniform width. Also, Iprefer to distribute the mass of the cup so that the latter has stableequilibrium with respect to thekpivot point 52, this result beingsecured by having the center of gravity of the cup located below thepoint of support.

From the foregoing, it will be apparent that I have devised atransformer wherein there are no wearing parts such as control edgeswhich tend to become rounded and thereby lose sensitlvity. The lmovementrequired is inconsequential and the means of support provide forfrictionless operation such that the provision of special frictionreducing means is unnecessary; Vibration is substantially avoidedbecause, not only are all of the parts firmly attached to the largebellows subject to impeller pressure, but the interior spaces, at 3| and32, lled with oil, serve to secure a substantial damping effect.Furthermore, the relation of component parts is such that closetolerances and clearances are not required with the result thatmanufacture, assembly and operation are facilitatet'i.` Aside from theseadvantages, the apparatus operates without any hydraulic reaction in thedirection of ap plied forces, this effect being due to the'radiallydirected escape voriiice which cannot under any condition givea component of force in an axial direction such as would be the casewith a piston valve having sharp land edges controlling sharpedgedcylinder, portsl As the cup valve is inherently stable with respect toits point of support and is designed to provide a self-rightinghydraulic moment, the escape orice will tend to maintain a uniformannular escape area. Furthermore, as the cup operates to give atransformed pressure without high frequency pulsations the life ofdeilectable parts, suchvas bellows elements, is increased.

While I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modicatlons without departing from thespirit thereof. and I desire, therefore, that only such limitationsshall be placed thereupon as are specifically set forth in the appendedclaims.

What I claim is:

1. In a governing system, pressure-rospov ve means; means lproviding aforce which varies in response to change in speed; means fortransforming changes in said force into changes of iiuid pressure andfor applying the latter to the pressure-responsive means; saidtransforming sponsive means and having an escape port whose extendingradially from the latter, means for maintaining iluid under pressure insaid space, and a member arranged in overlapping relation with respectto said seat to cover the exit end of the port and to cooperate with theseat to define an escape orifice; and means for applyingl said force tosaid member in a direction opposed to that of force if space pressureapplied thereto.

2. In a governing system, pressure-responsive means; means providing aforce which varies in response to change in speed; means fortransforming'changes in said force into changes of fluid pressure andfor applying the latter to the pressure-responsive means; saidtransforming means including structure providing an enclosed space incommunication with the pressure-responsive means and having an escapeport whose exit end is bounded circumferentially by a. seat extendingradially from the latter, means including an orifice for supplying iluidunder pressure to said space, and a member arranged in overlappingrelation with respect to said seat to cover the exit end of the port andto cooperate With the seat to dene an escape orice; means for applyingsaid force to said member in a direction opposed to the force of spacepressure applied thereto; and means responsive to temporary prime moverspeed change incident to load change to reduce the change in speed dueto load change.

3. In a governing system, pressure-responsive means; means providing aforce which varies in response to change in speed; means fortransforming changes in said force into changes of iiuid pressure andfor applying the latter to the pressure-responsive means; sagcttransforming means including structure providing an enclosed space incommunication with the pressure-responsive means and having an escapeport whose exit end is bounded circumferentially by a seat extendingradially from the latter, means including an orifice for supplying iiuidunder pressure to said space, and a member in overlapping relation withrespect to the exit end of the port and cooperating with the seat todenean escape orifice; means for applying said force to said member in adirection opposed to that of the force of space pressure appliedthereto; means providing a passage having'one end communieating withVsaid space and including an accumulator; and means associated with theother end of the last-named passage and responsive to fluid pressurethereof to apply a force to the covering member acting in the samedirection as said rst force in order to eiiect speed correction of theprime mover incident to change in load.

4. In a governing system, pressure-responsive means; means providing aforce which varies in response to change in speed; means fortransforming changes in said force into changes of fluid pressure andfor applying thellatter to the pressure-responsive means; saidtransforming means including structure providing an enclosed space incommunication with the pressure-responsive means and having an escapeport Whose outlet is bounded by an annular seat, means for maintainingiluid under pressure in said space,

and a member in covering relation with respect to the outlet end of theport and cooperating with said seat to define an annular escape orice;means for applying said force to said member in a. direction opposed tothat of the force of space pressure applied thereto; means providing apiston area or abutment for said member equal to and in opposed relationwith respect to the piston area thereof bounded by the annular orilce;means providing a pressure chamber for the first abutment or pistonarea; and means including a passage communicating with said space and anaccumulator cooperating with the pusage to provide for lagging ofchanges in pressure in said chamber relative to pressure changes in saidspace.

5. In a governing system, pressure-responsive means; means providing aforce which varies in response to change in speed; means fortransforming changes in said force into changes of fluid pressure andfor applying the latter to the pressure-responsive means; saidtransforming means including structure'providing an enclosed space incommunication with the pressure-responsive means and having an escapeport whose outlet end is bounded by an annular seat, means formaintaining fluid under pressure in said space, and a cup in coveringrelation with respect to the outlet end of said port and having a sharpannular edge cooperating with said seat to denne a radially-directedannular escape orince; a member having point bearing contact with thecup; and means for applying said force to the member. j

I 6. In a governing system, pressure-responsive means; means providing aforce which varies in forming changes in said force into changes oi.'fluid pressure and for applying the latter to the pressure-responsivemeans; said transforming means including structure providing an enclosedresponse to change in speed; means for transspace in communication withthe pressure-responsive means and having an escape port whose outlet endis bounded by an annular seat, means for maintaining fluid underpressure in said space, and a member in covering relation with respectto the outlet end of said port and co" 40 operating with said seat todenne an'annular escape orifice; a thrust member having point 1 responseto change in speed; means for transforming changes in said force intochanges of fluid pressure and for applying the latter to thepressure-responsive means; said transforming means including structureproviding an enclosed space in communication with thepressure-responsive means and having an escape port whose outlet end isbounded by an annular seat, means for maintaining l fluid under pressurein said space, and a member in vcovering relation with respect to theoutlet end of said port and cooperating with said seat to dene anVannular escape orince; a thrust member having a point bearing contactwith respect to said covering member; means for centering the thrustmember; means providing a piston area on the thrust member in opposedrelation to the piston area provided by the covering member and boundedby the annular orificel and equal to the latter piston area; meansproviding a pressure chamber for the first piston area; and meansincluding a passage communicating with said pressure space and providingfor the lagging of change in pressure in said chamber relative to changein pressure in said space.

8. In a governing system, pressure-responsive means; means providing aforce which varies in response to change in speed; means fortransforming changes in said force into changes of fluid pressure andfor applying the latter to the pressure-responsive means; saidtransforming means including structure providing an enclosed space incommunication with the pressure-responsive means and having an escapeport whose outlet end is bounded by an annular seat, means formaintaining uid under pressure in said space, and a cup in coveringrelation with respect to the outlet end of said port and having anannular edge cooperating with said seat to dene an annular escapeorifice; a member having point bearing contact relation withrespect tosaid cup; a. diaphragm for centering said member, said membe rhaving apiston area equal to and in opposed relation to the piston area providedby the cup and boundedby the annular orice; means providing a pressurechamber for the first piston area; a passage affording communicationbetween the chamber and said transformed uid pressure space; meansproviding an orifice for said passage; an accumulator communicating withthe passage between the oriilce and the pressure chamber; and means forapplying said force to said member 'in a direction opposed to that ofthe force o f space pressure applied to the cup.

OZRO NEWTON BRYANT.

